CHECKOUT AND INSTALLATION
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GAP IN
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PROCESS
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Figure
4-2.
Timing Diagram (Preferred fVlethod)'40(i-OO!i1-300
40G-OO!j1-400A
4. Alternate Method
a. This method is available as Ivlodification #M-115. It should be specified at the tinle the order is placed, but it is also feasible as a field modification.
b. Modification #M-115 can be used only in seven-channel tape units. In nine-channel Systeln 360 cOlnpatible units the preferred method must be used due to limitations imposed by the CRCC circuits.
c. This nlethod is sinlilar to the preferred nlethod, except that it uses the Count Enable input and does not use the EOR C olnmand input. Gap tilning must be done e:A'ternal to the tape unit, and the Gap in Process output renlains False.
INCREMENTAL/CONTINUOUS WRITING
Data can be entered in both the Increnlental and Continuous 1110de on the sanle tape. The transition fronl either l1lode to the other must take place following an IRG and with the stepper motor stopped. Then follow the appropriate instructions above.
REVlIND
1. Press REWIND Pushbutton. Tape will rewind until Load Point marker is sensed and then stop. Rewind cannot be stopped (except by turning off power) once initiated.
This is to prevent partial rewinding and subsequent possible destruction of data.
2. After tape has stopped it may be relnoved by manually con1pleting the rewind with power off or by pressing LOAD FORWARD quickly, followed by pressing REWIND.
Tape will then wind completely out of the lnachine and the reels will store
To avoid tape damage, always wait at least one second after the Load Point nlarker is sensed before activating any nlachine function. This allows the tape to stop completely.
SECTION V
MAINTENANCE
506-0011-200
SECTION V MAINTENANCE,
ROUTINE MAINTENANCE
Primarily, routine maintenance consists of keeping mechanical parts clean. At regular inter-vals, depending in length upon use of machine and cleanliness of machine environment, the following steps should be taken:
1. Clean head surface and entire guide plate area with soft cloth and a mild organic solvent such as IBM head cleaner.
2. C lean surface of pinch roller to remove accumulation of oxide with a similar solvent.
3. Remove any accumulation of dust within the main cover and on the panel.
It should be kept in mind that while incremental recorders are very reliable devices and can operate under conditions more adverse than high speed computer tape transports, dirt is always a major source of difficulty and potential error. The tape path must be kept as clean as possible.
All bearings in the machine are lubricated for life. No further lubrication should be attempted since ball bearing lubrication can be destroyed by oil.
CHECKOUT AND ADJUSTMENT PROCEDURE
Relatively few adjustments are required on Kennedy Incremental Recorders. These can be divided into two classes, mechanical adjustments and electrical adjustments. Electrical adjustments, if any, will be found in Sections VI and VII. Mechanical adjustment procedures are given below.
Mechanical Adjustments
Tension Arm Adjustment: Two tape tension arms are provided for sensing tape tension and providing a buffer loop to allow free tape motion. Tens ion arms are coupled to potentiometers which control reel motor torque to maintain tension constant. Adjust-ments required are:
1. Tension Arm Return Force (Ref. Figure 5-1)
Tension arms are spring loaded to provide proper tape tension. To set tape tension:
a. Swing arm to approximate center of arc.
b. Measure return force at the end of the arm with a spring scale.
c. Adjust anchor lug position for a spring scale reading of 4 oz. (113 gm). This setting will establish 2 oz. of tape tension.
2. Servo Potentiometer Angular Position (See Figure 5-1)
Tension arm is coupled to servo potentiometer by a shaft clamp. Potentiometer shaft extends through the panel and is slotted to accept a screwdriver. Servo potentiometer must be positioned to give proper motor torque.
a. Loosen shaft clamp lock screw until potentiometer shaft may be rotated with a screwdriver but still is snug enough to be rotated by tension arm. Press
LOAD FORWARD pushbutton.
b. Hold tension arm in approximate center of arc. Turn potentiometer shaft until torque produced by reel servo drops to zero.
c. Tighten clamp lock screw.
d. With tape in place energize servos. Note position assumed by tension arm.
If not close to center of arc, re-adjust potentiometer shaft to correct.
Note
Potentiometer shafts are accessible only with reels removed.
3. Tape Path Location
Tension arm rollers establish approximate tape path. To assure no skew is intro-duced this path must conform closely to guide path. To adjust:
a. Loosen lock nuts on roller shafts (Figure 5-1).
b. Measure height of rear edge of tape (closest to panel) at the guide plate. Tape should clear guide plate surface by 0.437" (1.72 cm) ±O. 005" (0.127 mm), and be parallel to guide plate surface throughout its length.
c. Adjust roller screw for correct tape height.
d. Lock roller screw with lock nut.
506-0011-300
SHAFf
ARM
LOCK SCREW
TENSION ARM CLAMP
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SHAFf CLAMPLOCK SCREW
ROLLER
/NCHORLUQ
SERVO
POTENTIOMETER
LOCK NUT
/
Figure 5-1. Tension Arm Adjustments
4. Capstan Drive Gear Mesh
Adjustment of Capstan Drive Gear Mesh is accomplished by rotating the stepper motor in its eccentric mounting. This adjustment should not be attempted unless there is strong reason to believe it is required. Gears are properly meshed when units leave the factory and should not require re-adjustment over long periods.
Mesh adjustment cannot be measured directly; it must be accomplished by feel.
With power off:
a. Loosen three clamp screws holding motor in place.
b. Rotate motor clockwise (from rear) to tighten mesh.
c. Rotate capstan shaft as motor is rotated to detect zero backlash setting . . d. Lock motor in place and check again for zero backlash and free rotation.
It should be possible to rotate motor from the capstan without difficulty.
e. If necessary, repeat procedure until zero backlash with free rotation is achieved. In the proper setting a slight "toothy" feel will be noticed.
506-0011-"'00
5. Pinch Roller Adjustment (Figure 5-2)
Two criteria must be met in adjusting pinch rollers: frictional force must be sufficient to drive tape adequately and pinch roller must be parallel to the capstan in order to pull the tape straight. To adjust parallelism:
a. With power applied to pinch roller or holding solenoid in energized position, adjust roller height adjusting screw until roller does not touch capstan.
b. Turn screw one-quarter turn more.
c. Lock with Loctite grade H.
Pressure should now be properly set. Check tape pull as follows:
a. Prepare a length of tape about two feet long.
b. Feed tape through guides and over head, through pinch roller/capstan.
c. Attach a spring scale to tape and press LOAD FORWARD button. Hold tape back until it slips at the drive.
d. Spring scale should read at least 6 oz. (170 gm). If not, rotate screw
506-0011-500
slightly and re-measure. Be sure pinch roller is well cleaned before adjusting.
CAPSTAN
ROLLER HEIGIIT
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PARALLELISM LOCK
SCREWS (2)
Figu,e 5-2. Pinch Rolle, Adjustments
Final parallelism adjustment is now made:
a. Using a length of tape, say, three feet long (about one meter), feed through machine as above.
b. Press LOAD FORWARD and observe tape motion. Tape should pull evenly through pinch roller/capstan with no tendency tO'skew either in or out.
c. If tape does not pull straight, re-adjust parallelism screws until straight motion is obtained. Tape will tend to move toward the tight side of engage-ment.
d. Lock screws in place and apply Loctite grade H.
e. Re-check as above after locking.
REPLACEMENT OF PARTS
In the event of damage to the machine, parts not normally expected to be replaced might require maintenance. The following discussion describes procedures for maintenance under these circumstances.
1. Servo Potentiometer Replacement
506-0011-600
a. Remove potentiometer by removing two screws holding potentiometer mounting plate. Remember to loosen shaft clamp screw in tension arm clamp.
b. Mount new potentiometer with lugs in same app~oximate location of old unit.
c. Return potentiometer and mounting plate to assembly replacing tension arm.
d. Return mounting screws. Be sure potentiometer shaft rotates freely after screws are tightened.
e. Go through adjustment procedure as outlined above.
2. Tension Roller
Under extreme circumstances shaft of tension arm roller may be bent. In this case it requires replacement.
a. Remove old roller together with shaft.
b. Install new roller and shaft.
c. Adjust as previously described in step 3.
3. Pinch Roller
After long service the pinch roller may become worn and require replacement.
To replace pinch roller:
a. Remove assembly from mounting surface by removing screws (item 1, Figure 5-3).
b. Remove pin (item 2) by means of a small hook formed from stiff wire.
c. Lift pinch roller yoke (item 3) clear of housing (item 4).
d. Remove retaining ring (item 5) from front of shaft.
e. Remove shaft (item 6) from rear of assembly, freeing pinch roller (item 7).
f. Replace pinch roller and re-as semble.
g. Re-adjust pinch roller as previously described in step 5.
Figure 5-3. Pinch Roller Replacement
608-0011-700
4. Capstan Assembly
In the event that through wear or other cause the capstan assembly needs replace-ment:
a. Remove old assembly by removing wires from terminal block and removing two mounting screws from front side of panel.
b. Replace with new assembly. Bearing must seat in counterbore on reverse side of mounting plate.
c. Re-adjust pinch roller (as previously described in step 5). Repair of capstan assemblies in the field is not advised. Return used assembly together with complete information to factory for credit.
5. Reel Hub Grip Ring (Figure 5-4)
A rubber ring is used as an expansion ring to hold the tape reel in place. If it should require replacement, simply pry old ring off without disassembling huh and snap new ring in its place.
6. Guides
If a guide becomes worn, it is usually adequate to simply loosen its mounting screw, turn the guide a few degrees, and re-tighten.
If complete replacement is desired, remove screw and guide. Replace with new guide; no adjustment is required.
7. Magnetic Head
Heads have very long life at speeds encountered in incremental recorders. If replacement is required:
a. Unplug head.
b. Remove two mounting screws.
c. Pass connector through hole in panel and remove head.
d. Replace with new head.
No adjustment of heads is possible or required. Return head to factory with complete details of cause for replacement. In some cases credit will be issued.
506-0011-800
RUBBER DBlVE lUNG
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LOOSEN REEL HUB LOCK COMPLETELY, BY TURNING CCW. BEFORE REMOVING THE RUBBER DRIVE RING.
Figure
5-4.Rubber Ring Drive Replacement
506-0011-900
SECTION VI
MECHANICAL
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